import React from 'react'

class Hello extends React.Component {
    render() {
        const todoList = ['react', 'redux', 'react-native']
        return (
            <div>
                计算：{ 3-1 }
                <h1 className="title">Hello React</h1>
                <ul>
                    { todoList.map(item => 
                        <li key={item}>{item}</li>    
                    )}
                </ul>
            </div>
        )
    }

}

export default Hello